It pisses me off when companies want charge 3% or more to pay them by credit card.  If you don’t want to take credit cards fine, but don’t profit from it!  Elavon through Costco only charges 1.99% + 25 ¢ (for phone transactions) so don’t lie and try to make profit from a credit card transaction.

California and about 10 other states were trying to prohibit these surcharges

But now, starting with the US Supreme Court, surcharges will probably be allowed.  (See Expressions Hair Design

Technically, Civil Code Section 1748.1(a) prohibits retailers from imposing a surcharge on customers who pay with a credit card, but allows them to offer discounts for cash or check.

There is a work around for merchants, under the first amendment and how this surcharge is advertised.  See 9th Circuit Opinion: